White light illumination device and method of manufacturing the same

Abstract

The present invention describes an apparatus and method for manufacturing a white light-emitting diode (LED) using a powder with characteristics of fluorescence to achieve a high-luminosity white LED. The LED emitting ultraviolet light is used as an excitation source, which excites a first powder with blue-green light, and a second powder with orange light. After that, a white light is produced by blending blue-green and orange light with the principle of complementary colors. For achieving the high-luminosity white LED, the invention adopts a suitable LED to be the excitation source with a suitable blending proportion. On the other hand, the implementation of the fluorescent powder with blue-green light can be modulated using a metal ion in the host lattice to change the ligard field of the crystal.

1 . A white light illumination device, comprising: 
 a light-emitting diode capable of emitting ultraviolet light;    a first fluorescent powder excited by the ultraviolet light from the light-emitting diode and emitting blue-green fluorescent light having a peak emission wavelength of about 470 to about 500 nm, a chemical formula of the first fluorescent powder being (Ba 1-x-y Eu x Sr y )MgAl 10 O 17 , where 0<x≦1, 0≦y≦1; and    a second fluorescent powder being excited by the ultraviolet light from the light-emitting diode and emitting orange fluorescent light having a peak emission wavelength of about 570 to about 600 nm, a chemical formula of the second fluorescent powder being (Ca,Eu,Mn)(PO 4 ) 3 Cl;    wherein the blue-green and the orange fluorescent lights combine to produce white light.    
   
   
       2 . The white light illumination device as claimed in  claim 1 , wherein one of plasma and an electron beam is used to generate the ultraviolet light.  
   
   
       3 . The white light illumination device as claimed in  claim 1 , wherein the white light illumination device is obtained by blending the first and the second fluorescent powders, using the light-emitting diode capable of emitting ultraviolet light as an excitation light source, and applying a driving current after encapsulating.  
   
   
       4 . The white light illumination device as claimed in  claim 1 , wherein the first fluorescent powder comprises substituting metallic ions with different ion radii to change a light emission wavelength thereof.  
   
   
       5 . A method for producing a white light lamination device, comprising: providing an ultraviolet light source; synthesizing a first fluorescent powder, wherein the first fluorescent powder emits a blue-green light having a peak wavelength of about 470 to about 500 nm by excitation with ultraviolet light emitted from the ultraviolet light source, a chemical formula of the first fluorescent powder being (Ba 1-x-y Eu x Sr y )MgAl 10 O 17  where 0<x≦1, 0≦y≦1; 
 synthesizing a second fluorescent powder, wherein the second fluorescent powder emits an orange light having a peak wavelength of about 570 to about 600 nm by excitation with ultraviolet light emitted from the ultraviolet light source, a chemical formula of the second fluorescent powder being (Ca,Eu,Mn)(PO 4 ) 3 Cl; and    blending the first and second fluorescent powders in predetermined proportions.    
   
   
       6 . The method for producing a white light lamination device as claimed in  claim 5 , wherein one of plasma and an electron beam is used to generate the ultraviolet light.  
   
   
       7 . The method for producing a white light lamination device as claimed in  claim 5 , wherein the first and the second fluorescent powders are made by one of a citrate gel method and a co-precipitation method.  
   
   
       8 . The method for producing a white light lamination device as claimed in  claim 5 , wherein the first fluorescent powder comprises substituting metallic ions with different ion radii to change a light emission wavelength thereof.